Is my combi boiler set-up normal?

[mk2phil]

Hi fellas,

Just moved into a new house which has recently had a potterton combi boiler installed. All radiators have TRV's fitted apart from the bathroom and main bedroom.

However, there is no room thermostat or programmer, which seems a bit odd to me?

The boiler has a very simple timer on its front control panel which has allowed me to control what times during the day it comes on, which isn't the end of the world. Still doesn't allow me to control 5/2 days like my old one did which was much more convenient.

Whats really stumped me though is that there is no room thermostat at all. It seems the only way I can effectivley control the temp of the house is to adjust the system temp control for the CH directly on the boiler? This doesn't feel right to me becuase if I wanted to maintain the house temp at say 18 deg throughout the night (we have a baby), I have to leave the boiler cycling all night becuase all it can measure is the heat output of the CH water and nothing else.

I'm new to combi boilers - my old house was a traditional open vented type with stat/programmer - so I dont know if this is correct or not?

Thanks for any advice,
Phil

 

[Whitespirit66]

The new boiler should really have been fitted with a room stat. Crazy not to with the price of gas today.

You have several options.

Keep the boiler's timer, and fit a wired or wireless room stat in hall or living room.

Get a programmable room stat to control heating timings as well as temp, and either remove boiler's timer, or set it to constant to allow new prog. stat to control times. Also either wired or wireless.


If you go for wireless, don't be tempted by cheaper makes. Go for something reliable like Drayton or Honeywell.

 

[mk2phil]

Thanks whitespirit.

I've been doing more reading and came across a few posts where people were suggesting that the boiler senses the return temp on the CH and shuts the boiler down when it reaches the set temp.

If this is true, wouldn't that be doing the same thing as a room stat anyway? I.e. the TRV's shut down when the desired rad temp is reached, therefore meaning that the returned CH water temp is high and this shuts down the boiler like a stat would?

I'm not arguing, I just want to understand it properly.

Cheers

 

[Whitespirit66]

I've been doing more reading and came across a few posts where people were suggesting that the boiler senses the return temp on the CH and shuts the boiler down when it reaches the set temp.

It's a very crude and inefficient way of controlling it. If the boiler control is set too low, then it may shut off as the first TRVs start to close, or vice versa.

The boiler control takes no account of how well the house is heated. You need a stat to turn the boiler off when the house is up to temp, this varies a lot according to outside temp.

A stat will save money and aggro.

 

[Corgigrouch]

No it isn't the same.... when the roomstat senses the room that it is in is warm enough, then all of the heating shuts down... the boiler won't fire... If you rely on the boilers own temperature sensor then it will still fire to heat the water in the pipework, whether you need it to heat them or not... Thus wasting energy.

 

[mk2phil]

thanks fellas - understood!